Using climate/weather data with the NLEAP model to manage soil nitrogen

Local climate/weather conditions can have profound effects on soil fertility management and leaching of nitrates. The application of simulation models together with appropriate climate and soil databases provides a mechanism to evaluate current and alternative management options and identify techniques that will minimize nitrate leaching. The Nitrate Leaching and Economic Analysis Package (NLEAP) model and databases were applied in the form of sensitivity analyses to rainfed climate conditions found in the midwest and to irrigated agriculture in the semiarid Great Plains. Model results supported with field validation data illustrate the importance of local climate/weather patterns on nitrogen management and nitrate leaching amounts and distributions. Site-specific management strategies appear to be necessary for optimal fertility management and control of nitrate leaching. Results obtained from short term transient and long term steady state runs with the NLEAP model illustrate how the model can be used in conjunction with appropriate climate databases as an aid to management decisions regarding control of nitrate nitrogen leaching.